There is also quite a business these days in republishing books with expired copyrights. They are in the public domain, free from any legal obligation to the original copyright holder, and there are plenty of publishers who are good at making low cost replicas of these old books.

Another of my interests is all forms of woodworking, with an emphasis on using hand tools. There are several other guys with similar interests who are doing quite well with reprinting replicas of 19th century and early 20th century craft books.

However, there's usually a new cover or new cover page that let's you know it is a modern replica.